People in interaction with others organize their perceptions of a social situation in terms of plans even when the others' plans are poorly formulated. They use their models of others' plans in formulating their own. Much of what occurs in discourse centers on a continual communication about and reformulation of one's own plans and one's own models of others' plans. Formal methods for describing and analyzing plans are now available and make it possible to be more explicit in formulating hypotheses about social interaction. Unfortunately, the classical formulations for planning are derived from a robot world model that fails to generalize sufficiently to account for typical human planning situations. By pushing the classical model, it is possible to create a model of planning that embodies concepts such as "mutual belief,""social episode," and "goal conflict." In applying this model to a simple dialogue, it becomes clear that elements of the model are necessary for modeling such dialogues, but not sufficient. More complex dialogues and texts will undoubtedly require further elaboration of the model. (Author/FL)